... :T-boltsStandard: GB37,1371type,1372type,1373type,1374type,1375 type,1376type,1377 typeGrade:Class 4.8, Class 6.8, Class 8.8 ... , Class 12.9StandardGB37, 1371type,1372type,1373type,1374type,1375 type,1376type,1377 typeColorsilver,plainTechnology:cold forging,heat treatment,Packing:in bulk,in ...